To bump this. You basically just increase the limits in both (or all four functions if we include osEepromLongRead and osEepromLondWrite) to around 0x0100 or higher.

0xE4164 -> Change: (for EEPROM Read subroutine)

Code

SLTIAT, $0041

And change the limit from $0041 to $0100. (If you know, 0x41 is the default eeprom limit. By calculating 0x41 * 8 (as each EEPROM Block is 8 bytes long) you get the EEPROM Address. So, basically it just checks if the address we write is less than 0x41 * 8. If yes, then it works, if not, you won't see your EEPROM being written or anything. Now, as said before, change the limit:

Code

SLTIAT, $0100

You do the same on 0xE3B04 (eeprom write function).

Next thing you need to know is the eeprom ram bank, which starts at 0x80207700. To test out, if our shit worked, we write some test code and write over the 0x41 limit or directly on it. 0x80207908 in our case. I do it in pseudo-code, cause asm seems not to be everyone's strength here:

If we press D-Pad Down mycoins is increased by one, the 2nd index of our temp array (2nd 4 byte block, right) is assigned to mycoins and then written to 0x41 * 8 in EEPROM. If you close the game now and look into your EEPROM (which is mostly stored directly in your Project64 1.6/Saves folder or in C:\Users\<YourName>\AppData\Local\VirtualStore\Program Files (x86)\Project64 1.6\Save.

If you open it up and look at 0x208, you should see your saved coin value (in hexadecimal, of course). Like here:

So, basically all you need is an array, which the 2nd index is later assigned to the target variable we want to write to eeprom. We can also read the eeprom with the very same method:

We assign mycoins with the 2nd index of tempreadarray obviously, as we stored our write array also with the 2nd index. So we read the 2nd index and assign it to mycoins.

In case you ask, 0x8033AF78 is a pointer to Message Queue. To be more specific, they actually provide a nice communication and synchronization mechanism. So, message queues are often used between threads and events.

To sum it up, you actually don't need to change any settings in PJ64. You can keep it on default.